"The mistakes we are making are criminal," he said. "We've got to get back to the basics and if the players need prove of what is needed in this division, it was there today.
"We did a lot of talking after Monday night's 3-0 defeat at Watford and we have worked on it. But to give away a free header in the last minute is disappointing. It should have been three points.
"We have to dig in and work hard and we have to be able to adjust and adapt. People thought we would be the whipping boys of this division after the Watford defeat but I think we have proved otherwise.
"The lads have to believe they can do the same again in this division as they did last season. They have to believe in passion and my boys can do better."
Sunderland manager Mick McCarthy claimed his side did not deserve to lose after twice hitting back to cancel out two wonder goals.
"Rangers scored two fantastic goals and you sometimes have to give credit to the opposition," he said. "But I felt we could have defended better.
"It would have been an injustice if we had not got something, but sometimes it does happen.
"I always felt we were going to have the lion's share of possession and that's what we did.
"It was strange that we scored from a set a set-piece with Kevin Kyle off the field and when you score two goals at home, you should get more than a point.
"Kevin is still struggling with his hip problem and he is seeing the specialist on Tuesday. We are monitoring his problem and it is a testimony to the effort that he puts in as we are struggling to get him fit."